Abstract:

A semiconductor device in which degradation due to permeation of water and
oxygen can be limited, e.g., a light emitting device having an organic
light emitting device (OLED) formed on a plastic substrate, and a liquid
crystal display using a plastic substrate. A layer to be debonded,
containing elements, is formed on a substrate, bonded to a supporting
member, and debonded from the substrate. A thin film is thereafter formed
on the debonded layer. The debonded layer with the thin film is adhered
to a transfer member. Cracks caused in the debonded layer at the time of
debonding are thereby repaired. As the thin film in contact with the
debonded layer, a film having thermal conductivity, e.g., film of
aluminum nitride or aluminum nitroxide is used. This film dissipates heat
from the elements and has the effect of preventing deformation and change
in quality of the transfer member, e.g., a plastic substrate.

Claims:

1. A semiconductor device comprising:a first substrate;a first thermal
conductivity film over the first substrate;a thin film transistor over
the first thermal conductivity film;a second thermal conductivity film
over the thin film transistor, anda second substrate over the second
thermal conductivity film.

2. A semiconductor device according to claim 1, further comprising an
oxide layer disposed between the first thermal conductivity film and the
thin film transistor.

3. A semiconductor device according to claim 1, further comprising a
light-emitting element disposed between the thin film transistor and the
second thermal conductivity film.

4. A semiconductor device according to claim 1, further comprising a
liquid crystal layer disposed between the thin film transistor and the
second thermal conductivity film.

5. A semiconductor device according to claim 1,wherein each of the first
thermal conductivity film and the second thermal conductivity film has a
light-transmitting property.

6. A semiconductor device according to claim 1,wherein the thin film
transistor includes a semiconductor layer and a gate electrode,wherein
the semiconductor layer includes a first impurity region, a second
impurity region, a third impurity region, and a channel formation
region,wherein the first impurity region and the second impurity region
are not overlapped with the gate electrode,wherein the third impurity
region and the channel formation region are overlapped with the gate
electrode, andwherein the second impurity region and the third impurity
region are disposed between the first impurity region and the channel
formation region.

7. A semiconductor device comprising:a first substrate;a first bonding
layer over the first substrate;a first thermal conductivity film over the
first bonding layer;a thin film transistor over the first thermal
conductivity film;a second thermal conductivity film over the thin film
transistor,a second bonding layer over the second thermal conductivity
film; anda second substrate over the second thermal conductivity film.

8. A semiconductor device according to claim 7, further comprising an
oxide layer disposed between the first thermal conductivity film and the
thin film transistor.

9. A semiconductor device according to claim 7, further comprising a
light-emitting element disposed between the thin film transistor and the
second thermal conductivity film.

10. A semiconductor device according to claim 7, further comprising a
liquid crystal layer disposed between the thin film transistor and the
second thermal conductivity film.

11. A semiconductor device according to claim 7,wherein each of the first
thermal conductivity film and the second thermal conductivity film has a
light-transmitting property.

12. A semiconductor device according to claim 7,wherein the thin film
transistor includes a semiconductor layer and a gate electrode,wherein
the semiconductor layer includes a first impurity region, a second
impurity region, a third impurity region, and a channel formation
region,wherein the first impurity region and the second impurity region
are not overlapped with the gate electrode,wherein the third impurity
region and the channel formation region are overlapped with the gate
electrode, andwherein the second impurity region and the third impurity
region are disposed between the first impurity region and the channel
formation region.

13. A semiconductor device according to claim 7,wherein the first bonding
layer is in contact with the first substrate and the first thermal
conductivity film, andwherein the second bonding layer is in contact with
the second substrate and the second thermal conductivity film.

14. A semiconductor device comprising:a first substrate;a first bonding
layer over the first substrate;a first thermal conductivity film over the
first bonding layer;a thin film transistor over the first thermal
conductivity film;a second thermal conductivity film over the thin film
transistor,a second bonding layer over the second thermal conductivity
film; anda second substrate over the second thermal conductivity
film,wherein each of the first substrate and the second substrate is a
plastic substrate, andwherein each of the first thermal conductivity film
and the second thermal conductivity film includes material selected from
the group consisting of aluminum nitride, aluminum oxide, aluminum
nitride oxide, aluminum oxynitride, and beryllium oxide.

15. A semiconductor device according to claim 14, further comprising an
oxide layer disposed between the first thermal conductivity film and the
thin film transistor.

16. A semiconductor device according to claim 14, further comprising a
light-emitting element disposed between the thin film transistor and the
second thermal conductivity film.

17. A semiconductor device according to claim 14, further comprising a
liquid crystal layer disposed between the thin film transistor and the
second thermal conductivity film.

18. A semiconductor device according to claim 14,wherein each of the first
thermal conductivity film and the second thermal conductivity film has a
light-transmitting property.

19. A semiconductor device according to claim 14,wherein the thin film
transistor includes a semiconductor layer and a gate electrode,wherein
the semiconductor layer includes a first impurity region, a second
impurity region, a third impurity region, and a channel formation
region,wherein the first impurity region and the second impurity region
are not overlapped with the gate electrode,wherein the third impurity
region and the channel formation region are overlapped with the gate
electrode, andwherein the second impurity region and the third impurity
region are disposed between the first impurity region and the channel
formation region.

20. A semiconductor device according to claim 14,wherein the first bonding
layer is in contact with the first substrate and the first thermal
conductivity film, andwherein the second bonding layer is in contact with
the second substrate and the second thermal conductivity film.

21. A semiconductor device comprising:a transfer member;a supporting
member;a first thermal conductivity film;a second thermal conductivity
film, anda thin film transistor disposed between the transfer member and
the supporting member, and disposed between the first thermal
conductivity film and the second thermal conductivity film.

22. A semiconductor device according to claim 21, further comprising a
first bonding layer disposed between the transfer member and the thin
film transistor, and a second bonding layer disposed between the
supporting member and the thin film transistor.

23. A semiconductor device according to claim 21, further comprising a
light-emitting element disposed between the thin film transistor and the
supporting member.

24. A semiconductor device according to claim 21,wherein each of the first
thermal conductivity film and the second thermal conductivity film has a
light-transmitting property.

25. A semiconductor device according to claim 21,wherein each of the first
thermal conductivity film and the second thermal conductivity film
includes metal.

26. A semiconductor device according to claim 21,wherein each of the first
thermal conductivity film and the second thermal conductivity film
includes material selected from the group consisting of aluminum nitride,
aluminum oxide, aluminum nitride oxide, aluminum oxynitride, and
beryllium oxide.

27. A semiconductor device comprising:a transfer member;a supporting
member;a first thermal conductivity film;a second thermal conductivity
film,a thin film transistor disposed between the transfer member and the
supporting member, and disposed between the first thermal conductivity
film and the second thermal conductivity film, andan oxide layer disposed
between the transfer member and the thin film transistor, and disposed
between the first thermal conductivity film and the thin film transistor.

28. A semiconductor device according to claim 27, further comprising a
first bonding layer disposed between the transfer member and the thin
film transistor, and a second bonding layer disposed between the
supporting member and the thin film transistor.

29. A semiconductor device according to claim 27, further comprising a
light-emitting element disposed between the thin film transistor and the
supporting member.

30. A semiconductor device according to claim 27,wherein each of the first
thermal conductivity film and the second thermal conductivity film has a
light-transmitting property.

31. A semiconductor device according to claim 27,wherein each of the first
thermal conductivity film and the second thermal conductivity film
includes metal.

32. A semiconductor device according to claim 27,wherein each of the first
thermal conductivity film and the second thermal conductivity film
includes material selected from the group consisting of aluminum nitride,
aluminum oxide, aluminum nitride oxide, aluminum oxynitride, and
beryllium oxide.

33. A semiconductor device comprising:a transfer member;a supporting
member;a first thermal conductivity film;a second thermal conductivity
film,a thin film transistor disposed between the transfer member and the
supporting member, and disposed between the first thermal conductivity
film and the second thermal conductivity film, andan oxide layer disposed
between the transfer member and the thin film transistor, and disposed
between the first thermal conductivity film and the thin film
transistor,wherein each of the transfer member and the supporting member
includes plastic.

34. A semiconductor device according to claim 33, further comprising a
first bonding layer disposed between the transfer member and the thin
film transistor, and a second bonding layer disposed between the
supporting member and the thin film transistor.

35. A semiconductor device according to claim 33, further comprising a
light-emitting element disposed between the thin film transistor and the
supporting member.

36. A semiconductor device according to claim 33,wherein each of the first
thermal conductivity film and the second thermal conductivity film has a
light-transmitting property.

37. A semiconductor device according to claim 33,wherein each of the first
thermal conductivity film and the second thermal conductivity film
includes metal.

38. A semiconductor device according to claim 33,wherein each of the first
thermal conductivity film and the second thermal conductivity film
includes material selected from the group consisting of aluminum nitride,
aluminum oxide, aluminum nitride oxide, aluminum oxynitride, and
beryllium oxide.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]This application is a continuation application of U.S. application
Ser. No. 11/201,087, filed Aug. 11, 2005, now allowed, which is a
divisional of U.S. application Ser. No. 10/199,496, filed Jul. 22, 2002,
now U.S. Pat. No. 7,045,438, which claims the benefit of foreign priority
applications filed in Japan as Serial No. 2001-228353 on Jul. 27, 2001
and Serial No. 2001-300021 on Sep. 28, 2001, all of which are
incorporated by reference.

BACKGROUND OF THE INVENTION

[0002]1. Field of the Invention

[0003]The present invention relates to a semiconductor device having a
circuit consisted of a thin film transistor (hereinafter, referred to as
TFT) in which the peeled off layer peeled off has been pasted and
transferred on a base member and a method of manufacturing the
semiconductor device. For example, the present invention relates to an
electro-optic device that is represented by a liquid crystal module, a
light emitting device that is represented by an EL module and an
electronic equipment on which such a device is mounted as a part.

[0004]It should be noted that in the present specification, the term
"semiconductor device" indicates a device in general capable of
functioning by utilizing the semiconductor characteristics, and an
electro-optic device, a light emitting device, a semiconductor circuit
and an electronic equipment are all semiconductor devices.

[0005]2. Related Art

[0006]In recent years, a technology constituting a thin film transistor
(TFT) using a semiconductor thin film (in the range from about a few to a
few hundreds nm in thickness) formed on the substrate having an
insulating surface has drawn attention. A thin film transistor is widely
applied to electronic devices such as an IC, an electro-optic device or
the like, and particularly, there is an urgent need to be developed as a
switching element for an image display device.

[0007]Although as for applications utilizing such an image display device,
a variety of applications are expected, particularly, its utilization for
portable apparatuses has drawn the attention. At present, although many
glass substrates and quartz substrates are utilized, there are defaults
of being easily cracked and heavy. Moreover, the glass substrates and
quartz substrates are difficult to be made larger in therms of conducting
a mass-production, and these are not suitable for that. Therefore, the
attempt that a TFT element is formed on a substrate having flexibility,
representatively, on a flexible plastic film has been performed.

[0008]However, since the heat resistance of a plastic film is low, it
cannot help lowering the highest temperature of the process. As a result,
at present, a TFT is formed which has not so excellent electric
characteristics compared with those formed on the glass substrates.
Therefore, a liquid crystal display device and light emitting element
having a high performance by utilizing a plastic film have not been
realized yet.

[0009]If a light emitting device or a liquid crystal display device
constituted of an organic light emitting device (OLED) formed on a
flexible substrate such as a plastic film can be fabricated, it can be
obtained as a thin lightweight device and can be used in a display having
a curved surface, a show window, etc. Use of such a device is not limited
to use as a portable device, and the range of uses of such a device is
markedly wide.

[0010]However, substrates made of plastics ordinarily have permeability to
water and oxygen, which act to accelerate degradation of the organic
light emitting layer. Therefore, light emitting devices using plastic
substrates tend to have a shorter life. By considering this problem, a
method has been used in which an insulating film of silicon nitride or
silicon nitroxide is formed between a plastic substrate and an OLED to
prevent mixing of water and oxygen in the organic light emitting layer.

[0011]Also, generally speaking, substrates formed of plastic film or the
like are not resistant to heat. If the temperature at which an insulating
film of silicon nitride or silicon nitroxide is formed on a plastic
substrate is excessively high, the substrate deforms easily. If the film
forming temperature is excessively low, a reduction in film quality
results and it is difficult to effectively limit permeation of water and
oxygen. There is also a problem in that when a device formed on a plastic
film substrate or the like is driven, heat is locally produced to deform
a portion of the substrate or to change the quality thereof.

[0012]Further, if the thickness of the insulating film of silicon nitride
or silicon nitroxide is increased in order to prevent permeation of water
and oxygen, a larger stress is caused in the film and the film cracks
easily. If the film thickness is large, the film cracks easily when the
substrate is bent. Also, a layer to be debonded may crack when it is bent
at the time of separation from the substrate.

SUMMARY OF THE INVENTION

[0013]In view of the above-described problems, an object of the present
invention is to provide semiconductor device in which deterioration due
to permeation of water and oxygen can be limited, for example, a light
emitting device having an OLED formed on a plastic substrate or a liquid
crystal display device using a plastic substrate.

[0014]According to the present invention, a layer to be debonded,
containing elements, is formed on a substrate, bonded to a supporting
member, and debonded from the substrate, a thin film is thereafter formed
in contact with the debonded layer, and the debonded layer with the thin
film is adhered to a transfer member The thin film is grown in contact
with the debonded layer to repair cracks caused in the debonded layer at
the time of debonding. As the thin film in contact with the debonded
layer, a film having thermal conductivity, e.g., film of aluminum nitride
or aluminum nitroxide is used. This film dissipates heat from the
elements and therefore has the effect of limiting degradation of the
elements as well as the effect of preventing deformation and change in
quality of the transfer member 22, e.g., a plastic substrate. The film
having thermal conductivity also has the effect of preventing mixing of
impurities such as water and oxygen from the outside.

[0015]An arrangement 1 of the present invention disclosed in this
specification is a light emitting device characterized by having, on a
substrate having an insulating surface, a light emitting element having a
cathode, an organic compound layer in contact with the cathode, and an
anode in contact with the organic compound layer, an insulating film in
contact with the anode, and a film formed in contact with the insulating
film and having thermal conductivity.

[0016]An arrangement 2 of the present invention is a light emitting device
characterized by having a substrate having an insulating surface, a
bonding layer in contact with the substrate, a film formed in contact
with the bonding layer and having thermal conductivity and an insulating
film in contact with the film having thermal conductivity, and a light
emitting element formed on the insulating film, the light emitting
element having a cathode, an organic compound layer in contact with the
cathode, and an anode in contact with the organic compound layer.

[0017]Each of the above-described arrangements is characterized in that
the film having thermal conductivity comprises a film transparent or
translucent to visible light.

[0018]Also, each of the above-described arrangements is characterized in
that the film having thermal conductivity is formed of a nitride
containing aluminum, a nitroxide containing aluminum, or an oxide
containing aluminum. As the film having thermal conductivity, a
multilayer film formed of a combination of films of these materials may
be used. For example, a multilayer of aluminum nitride (AlN) and aluminum
nitroxide (AlNXOY (X>Y)), or a multilayer of aluminum
nitroxide (AlNXOY (X>Y)) and aluminum oxynitride
(AlNXOY (X<Y)) may be used.

[0019]Also, each of the above-described arrangements is characterized in
that the film having thermal conductivity comprises a film containing at
least nitrogen and oxygen, and that the composition ratio of oxygen to
nitrogen in the film is 0.1 to 30%.

[0020]Also, each of the above-described arrangements is characterized in
that the substrate having an insulating surface comprises a plastic
substrate or a glass substrate.

[0021]An arrangement 3 of the present invention is a semiconductor device
characterized by having a transfer member, a first bonding layer in
contact with the transfer member, a film formed in contact with the first
bonding layer and having thermal conductivity, an insulating film in
contact with the film having thermal conductivity, a layer containing
elements on the insulating layer, a second bonding layer (a sealing
material or the like) in contact with the layer containing elements, and
a supporting member in contact with the second bonding layer.

[0022]In the above-described arrangement, it is characterized in that if a
liquid crystal display is fabricated, the supporting member is an opposed
substrate, the elements are thin-film transistors connected to pixel
electrodes, and a space between the pixel electrodes and the transfer
member is filled with a liquid crystal material. As the transfer member
and the opposed substrate, a plastic substrate or a glass substrate may
be used.

[0023]An arrangement of the present invention relating to a method of
fabricating a semiconductor device for realizing the structure in each of
the above-described arrangements 1 to 3 includes:

[0024]a step of forming a nitride layer on a substrate;

[0025]a step of forming an oxide layer on the nitride layer;

[0026]a step of forming an insulating layer on the oxide layer;

[0027]a step of forming a layer containing elements on the insulating
layer;

[0028]a step of bonding a supporting member to the layer containing
elements, and thereafter debonding the supporting member from the
substrate by a physical means at a position in the oxide layer or at an
interface on the oxide layer;

[0029]a step of forming a film having thermal conductivity on the
insulating layer or the oxide layer; and

[0030]a step of bonding a transfer member to the film having thermal
conductivity to interpose the elements between the supporting member and
the transfer member.

[0031]In this specification, "physical means" refers to a means recognized
not by chemistry but by physics, more specifically a dynamic means or
mechanical means having a process capable of reducing to a dynamic law,
i.e., a means capable of changing some dynamic energy (mechanical
energy). However, it is necessary that, at the time of debonding by a
physical means, the strength of bonding between the oxide layer and the
nitride layer be smaller than the strength of bonding between the oxide
layer and the supporting member.

[0032]The above-described arrangement relating to the method of
fabricating a semiconductor device is characterized in that the film
having thermal conductivity is formed of a nitride containing aluminum, a
nitroxide containing aluminum, or an oxide containing aluminum. As the
film having thermal conductivity, a multilayer film formed of a
combination of films of these materials may be used.

[0033]The above-described arrangement relating to the method of
fabricating a semiconductor device is also characterized in that the
nitride layer contains a metallic material, and that the metallic
material is a single layer of an element selected from the group
consisting of Ti, Al, Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Ru, Rh, Pd, Os,
Ir, and Pt, an alloy or a chemical compound having the element as a main
component, or a multilayer formed of such materials.

[0034]The above-described arrangement relating to the method of
fabricating a semiconductor device is also characterized in that a heat
treatment or a treatment using irradiation with laser light is performed
before debonding by the physical means.

[0035]The above-described arrangement relating to the method of
fabricating a semiconductor device is also characterized in that the
oxide layer is a single layer of a silicon oxide material or a metallic
oxide material, or a multilayer of these materials.

[0036]The above-described arrangement relating to the method of
fabricating a semiconductor device is also characterized in that the
elements are thin-film transistors having a semiconductor layer as an
active layer, and that the step of forming the semiconductor layer
includes crystallizing a semiconductor layer of an amorphous structure by
a heat treatment or a treatment using irradiation with laser light to
obtain a semiconductor layer of a crystalline structure.

[0037]The above-described arrangement relating to the method of
fabricating a semiconductor device is also characterized in that if a
liquid crystal display is fabricated, the supporting member is an opposed
substrate, the elements have pixel electrodes, and a space between the
pixel electrodes and the opposed substrate is filled with a liquid
crystal material.

[0038]In the above-described arrangement relating to the method of
fabricating a semiconductor device, if a light emitting device using an
element typified by an OLED is fabricated, it is desirable that the light
emitting element be completely isolated from the outside with the
supported member used as a sealing member to prevent materials such as
water and oxygen which accelerate degradation of an organic compound
layer from entering from the outside. Specifically, in such a case, it is
characterized in that the element is a light emitting element.

[0039]In each of the above-described arrangements, to facilitate
debonding, a heat treatment or a treatment using irradiation with laser
light may be performed before debonding by the physical means. In such a
case, a material capable of absorbing laser light may be selected as the
material of the nitride layer and the interface between the nitride and
the oxide may be heated to make separation easier. However, if laser
light is used, a transparent material is used to form the substrate.

[0040]To facilitate debonding, a granular oxide material may be provided
on the nitride layer and an oxide layer for covering the granular oxide
material may be provided, thus making separation easier.

[0041]The transfer member referred to in this specification is a member
bonded to the debonded layer after debonding. The base material of the
transfer member is not particularly specified. It may be a material of
any composition, e.g., plastic, glass, metal, or ceramics. The supporting
member referred to in this specification is a member bonded to the layer
to be debonded when the layer is debonded by a physical means. The base
material of the supporting member is not particularly specified. It may
be a material of any composition, e.g., a plastic, glass, a metal, or a
ceramic. The shape of the transfer member and the shape of the supporting
member are not limited to a particular one. Each of the transfer member
and the supporting member may have a flat surface or a curved surface,
may be flexible, and may have the shape of a film. If it is desirable to
achieve a reduction in weight with the highest priority, a plastic
substrate in film form, e.g., a plastic substrate made of polyethylene
terephthalate (PET), polyether sulfone (PES), polyethylene naphthalate
(PEN), polycarbonate (PC), nylon, polyetheretherketone (PEEK),
polysulfone (PSF), polyether imide (PEI), polyallylate (PAR), or
polybutylene terephthalate (PBT) is preferred.

[0042]The present invention can be carried out without limiting the
bonding method. Another arrangement relating to a method of fabricating a
semiconductor device for realizing the structure in each of the
above-described arrangements 1 to 3 includes:

[0043]a step of forming on a substrate a layer to be debonded containing
elements;

[0044]a step of bonding a supporting member to the layer to be debonded;

[0045]a step of debonding the supporting member from the substrate by a
physical means; and

[0046]a step of forming a film having thermal conductivity in contact with
the layer to be debonded.

[0047]As the debonding method in the above-described arrangements, a
well-known technique can be used. Examples of such a technique are a
method in which a separation layer is provided between the layer to be
debonded and the substrate, and in which the separation layer is removed
by a chemical solution (etchant) to separate the layer to be debonded
from the substrate, and a method in which a separation layer formed of an
amorphous silicon (or polysilicon) is provided between the layer to be
debonded and the substrate, and in which the separation layer is
irradiated with laser light passing through the substrate to release
hydrogen contained in the amorphous silicon, whereby a space for
separation between the layer to be debonded and the substrate is formed.
In the case of separation using laser light, it is desirable that the
elements contained in the layer to be debonded be formed by setting the
heat treatment temperature to 410° C. or lower to avoid release of
hydrogen before debonding.

[0048]In this specification, "laser light" refers to laser light generated
from a laser light source, e.g., a solid-state laser such as a YAG laser
or YVO4 laser, or a gas laser such as an excimer laser. The mode of
laser oscillation may be either of continuous oscillation or pulse
oscillation. Any beam shape, e.g., line irradiation or spot irradiation
may be used. Also, the scanning method is not particularly specified.

[0049]Still another arrangement relating to a method of fabricating a
semiconductor device for realizing the structure in each of the
above-described arrangements 1 to 3 includes:

[0050]a step of forming on a substrate a layer to be debonded containing
elements;

[0051]a step of bonding a supporting member to the layer to be debonded;

[0052]a step of attaching a flexible printed circuit (FPC) to a portion of
the layer to be debonded;

[0053]a step of fixing the supporting member by covering a connection
between the FPC and the layer to be debonded with an organic resin; and

[0054]a step of debonding the supporting member from the substrate by a
physical means.

[0055]The above-described arrangement includes, after the debonding step,
a step of forming a film having thermal conductivity in contact with the
debonded layer, and a step of bonding a transfer member to the film
having thermal conductivity to interpose the debonded layer between the
supporting member and the transfer member.

BRIEF DESCRIPTION OF THE DRAWINGS

[0056]In the accompanying drawings:

[0057]FIGS. 1A, 1B, and 1C are diagrams showing fabricating steps in
accordance with the present invention;

[0058]FIGS. 2A, 2B, and 2C are diagrams showing fabricating steps in
accordance with the present invention;

[0078]As the substrate 10 shown in FIG. 1A, a glass substrate, a quartz
substrate, a ceramic substrate or the like may be used. A silicon
substrate, a metallic substrate or a stainless substrate may
alternatively be used.

[0079]First, the nitride layer 11 is formed on the substrate 10, as shown
in FIG. 1A. A nitride material containing a metallic material is used as
the nitride layer 11. A typical example of the metallic material is a
single layer of an element selected from the group consisting of Ti, Al,
Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Ru, Rh, Pd, Os, Ir, and Pt, an alloy
or a chemical compound having the element as a main component, or
multiple layers of such materials. A single layer of a nitride of the
element, e.g., titanium nitride, tungsten nitride, tantalum nitride or
molybdenum nitride, or multiple layers of such materials may be used as
the nitride layer 11. A metallic layer formed of tungsten may be used in
place of the nitride layer 11.

[0080]Subsequently, the oxide layer 12 is formed on the nitride layer 11.
A typical example of a material used to form the oxide layer 12 is
silicon oxide, silicon oxynitride or an oxide of a metal. To form the
oxide layer 12, any of film forming methods such as sputtering, plasma
CVD and application may be used.

[0081]According to the present invention, it is important to make the
oxide layer 12 and the nitride layer 11 have different film stresses. The
film thickness of each layer is appropriately selected from the range of
1 to 1000 nm to adjust the film stress in the layer. While an example of
the structure in which the nitride layer 11 is formed in contact with the
substrate 10 and which is selected for simplification of the process is
shown in FIG. 1, an insulating layer or a metallic layer capable of
functioning as a buffer layer may be formed between the substrate 10 and
the nitride layer 11 to improve the adhesion to the substrate 10.

[0082]Subsequently, a layer to be debonded is formed on the oxide layer
12. The layer to be debonded may be formed as a layer containing various
elements (a thin-film diode, a photoelectric conversion element having a
silicon PIN junction, silicon resistance element, etc.) typified by a
TFT. A heat treatment may be performed on the layers in such a
temperature range that the substrate 10 can withstand. In the present
invention, even though the film stress in the oxide layer 12 and the film
stress in the nitride layer 11 are different, film separation or the like
is not caused by a heat treatment in the process of forming the layer to
be debonded. As the layer to be debonded, the elements 14a and 14b for a
drive circuit 23 and the element 14c in a pixel portion 24 are formed on
the base insulating layer 13, the OLED 15 which connects electrically to
the element 14 of the pixel portion 24 is formed, and the interlayer
insulating film 16 having a thickness of 10 to 1000 nm is formed so as to
cover the OLED (FIG. 1A).

[0083]If irregularities are formed in the surface after formation of the
nitride layer 11 and the oxide layer 12, the surface may be flattened
before or after the base insulating layer is formed. Flattening has the
effect of improving coverage in the layer to be debonded and, hence, the
effect of stabilizing element characteristics in the case where the layer
to be debonded containing elements is formed. Therefore it is preferable
to perform flattening. As a treatment for this flattening, etchback,
i.e., flattening by etching or the like after formation of an applied
film (resist film or the like), chemical mechanical polishing (CMP), or
the like may be performed.

[0084]Subsequently, a film 17 having thermal conductivity is formed on the
interlayer insulating film 16 (FIG. 1B). The film 17 having thermal
conductivity may be formed adjacently to the OLED 15 instead of being
formed on the interlayer insulating layer 16. If the film 17 is formed
adjacently to the OLED 15, it is preferred that the film 17 having
thermal conductivity be an insulating film. As the film 17 having thermal
conductivity, aluminum nitride (AlN), aluminum nitroxide
(AlNXOY (X>Y)), aluminum oxynitride (AlNXOY
(X<Y)), aluminum oxide (AlO) or beryllium oxide (BeO), for example,
may be used. If aluminum nitroxide (AlNXOY (X>Y)) is used,
it is preferred that the composition ratio of oxygen to nitride in the
film be 0.1 to 30%. It is also preferred that the film 17 having thermal
conductivity be a film transparent or translucent to visible light. In
this embodiment mode, an aluminum nitride (AlN) film having a
light-transmitting property and having a markedly high thermal
conductivity of 2.85 W/cmK and an energy gap of 6.28 eV (RT) is formed by
sputtering. For example, an aluminum nitride (AlN) target is used and
film forming is performed in an atmosphere in which argon gas and
nitrogen gas are mixed. Alternatively, film forming may be performed in a
nitrogen gas atmosphere by using an aluminum (Al) target. The film 17
having thermal conductivity also has the effect of preventing materials
such as water and oxygen which accelerate degradation of OLED 15 from
entering from the outside.

[0085]FIG. 15 shows the transmittance of AlNXOY film having a
thickness of 100 nm. As shown in FIG. 15, the light-transmitting property
of the AlNXOY film is markedly high (the transmittance in the
visible light region is 80 to 90%) and does not obstruct emission of
light from the light emitting element.

[0086]According to the present invention, the AlNXOY film is
formed by sputtering, for example, in an atmosphere in which argon gas,
oxygen gas and nitrogen gas are mixed, with an aluminum nitride (AlN)
used as a target. The AlNXOY film may have several atomic
percent or more, preferably 2.5 to 47.5 atm % of nitrogen. The nitrogen
concentration can be adjusted by suitably controlling sputtering
conditions (substrate temperature, raw-material gas, gas flow rate, film
forming pressure, and the like). FIG. 16 shows the composition of the
AlNXOY film obtained in this manner and analyzed by electron
spectroscopy for analysis (ESCA). Alternatively, film forming may be
performed in an atmosphere containing nitrogen gas and oxygen gas by
using an aluminum (Al) target. The film forming method is not limited to
sputtering. Evaporation or any other known technique may be used.

[0087]To confirm the water/oxygen blocking effect of the AlNXOY
film, an experiment was made in which a sample having an OLED sealed on a
film substrate with a 200 nm thick AlNXOY film and a sample
having an OLED sealed on a film substrate with a 200 nm thick SiN film
were prepared and changes of the samples with time in a water vapor
atmosphere heated at 85 degrees were examined. The life of the OLED in
the sample having the AlNXOY film was longer than that of the
OLED in the sample having the SiN film. The former OLED was able to emit
light for a longer time. From the results of this experiment, it can be
understood that the AlNXOY film is more effective than the SiN
film in preventing materials such as water and oxygen which accelerate
degradation of the organic compound layer from entering from the outside
of the apparatus. In addition, AlN and AlNXOY are more
difficult to crack than SiN. Therefore, A film formed of AlN or
AlNXOY is more preferable than a film formed of SiN for
attaching to a plastic substrate.

[0088]To confirm the alkali metal blocking effect of the AlNXOY
film, another experiment was made in which a 50 nm thick thermally
oxidized film was formed on a silicon substrate; a 40 nm thick
AlNXOY film was formed on the thermally oxidized film; an
aluminum electrode containing Li was formed on the AlNXOY film;
an aluminum electrode containing Si was formed on the silicon substrate
surface opposite from that surface on which the films were formed; and
the sample was heat-treated at 300° C. for one hour and then
underwent a BT stress test (±1.7 MV/cm, 150° C., 1 hour). A MOS
characteristic (C-V characteristic) was thereby measured. FIG. 17 shows
the results of this experiment. In the C-V characteristic shown in FIG.
17, a shift in the plus direction occurred when a plus voltage, i.e.,
+BT, was applied. It was confirmed therefrom that the cause of the shift
was not Li, and that the AlNXOY film had an alkali metal
blocking effect. For comparison, an AlLi alloy was formed on the MOS with
an insulating film (100 nm thick silicon nitride film) interposed
therebetween, and changes in MOS characteristic were also examined. FIG.
18 shows the results of this experiment. In the C-V characteristic shown
in FIG. 18, a large shift in the minus direction occurred when a plus
voltage, i.e., +BT, was applied. It is thought that a major cause of this
shift is mixture of Li in the active layer.

[0089]A supporting member 19 for fixing the layer to be debonded to enable
stripping of the substrate 10 by a physical means is adhered by using a
bonding layer 18 of an epoxy resin or the like (FIG. 1C). This step is
based on the assumption that the mechanical strength of the layer to be
debonded is not sufficiently high. If the mechanical strength of the
layer to be debonded is sufficiently high, the layer to be debonded can
be debonded without a supporting member on which the layer is fixed.

[0090]Subsequently, the substrate 10 on which the nitride layer 11 is
formed is stripped off by a physical means. It can be stripped off by a
comparatively small force since the film stress in the oxide layer 12 and
the film stress in the nitride layer 11 are different from each other.
While strength of bonding between the nitride layer and the oxide layer
is high enough to maintain bonding under thermal energy, the film
stresses in the nitride and oxide layers are different from each other
and a strain due to the stresses exists between the nitride and oxide
layers. Therefore, the bonding between the nitride and oxide layers is
not strong under dynamic energy and this condition is most suitable for
separation. Thus, the layer to be debonded, formed on the oxide layer 12,
can be separated from the substrate 10. FIG. 2A shows a state after
debonding. This debonding method enables not only debonding of a
small-area layer to be debonded but also high-yield debonding through the
entire area of a large-area layer to be debonded. Debonding can be
performed in the same manner even in a case where a metallic layer formed
of tungsten is used in place of the nitride layer 11.

[0091]A film 20 having thermal conductivity is again formed on the surface
from which the substrate has been stripped off (FIG. 2B). Cracks caused
at the time of debonding can be repaired by using the film 20 having
thermal conductivity. As the film 20 having thermal conductivity,
aluminum nitride (AlN), aluminum nitroxide (AlNXOY (X>Y)),
aluminum oxynitride (AlNXOY (X<Y)), aluminum oxide (AlO) or
beryllium oxide (BeO), for example, may be used. It is preferred that the
film 20 having thermal conductivity be a film transparent or translucent
to visible light. In this embodiment mode, an aluminum nitride (AlN) film
having a markedly high thermal conductivity of 2.85 W/cmK and an energy
gap of 6.28 eV (RT) is formed by sputtering. The film 20 having thermal
conductivity also has the effect of preventing materials such as water
and oxygen which accelerate degradation of OLED 15 from entering from the
outside.

[0092]The structure in which the OLED 15 is interposed between the two
layers of films 17 and 20 having thermal conductivity is thus formed to
completely isolate the OLED 15 from the outside. However, a structure in
which only one of the two layers of films 17 and 20 is formed may
alternatively be used.

[0093]The film thickness of each of the two layers of films 17 and 20
having thermal conductivity be set as desired in the range of 20 nm to 4
μm.

[0094]Subsequently, the debonded layer is attached to a transfer member 22
by a bonding layer 21 such as an epoxy resin. In this embodiment mode, a
plastic film substrate is used as the transfer member 22 in order that
the total weight of the light emitting device be reduced. If the
mechanical strength of the debonded layer is sufficiently high, it is not
necessary to specially provide the transfer member.

[0095]Thus, the light emitting device having the OLED formed on the
flexible plastic substrate is completed. Since in the structure of this
light emitting device, the elements 14a to 14c and the OLED 15 are
interposed between the two layers of films 17 and 20 having thermal
conductivity, heat produced by the OLED 15 and the elements 14a to 14c
can be dissipated. The films 17 and 20 having thermal conductivity are
also capable of limiting degradation due to permeation of water and
oxygen. If necessary, the supporting member or the transfer member is cut
to be formed into a desired shape. A flexible printed circuit (FPC) (not
shown) is attached to the debonded layer by using a well-known technique.
The FPC may be attached before debonding of the layer to be debonded
instead of being attached after debonding. Also, to increase the
mechanical strength of bonding between the FPC and the layer to be
debonded, an organic resin or the like may be formed to fix the FPC by
covering the bonding portion between the FPC and the layer to be
debonded.

[0096]The transfer member referred to in this specification is a member
bonded to the debonded layer after debonding. The base material of the
transfer member is not particularly specified. It may be a material of
any composition, e.g., a plastic, glass, a metal, or a ceramic. The
supporting member referred to in this specification is a member bonded to
the layer to be debonded when the layer is debonded by a physical means.
The base material of the supporting member is not particularly specified.
It may be a material of any composition, e.g., a plastic, glass, a metal,
or a ceramic. The shape of the transfer member and the shape of the
supporting member are not limited to a particular one. Each of the
transfer member and the supporting member may have a flat surface or a
curved surface, may be flexible, and may have the shape of a film. If
weight saving is the top priority, a film-type plastic substrate, for
example, a plastic substrate including polyethylene terephthalate (PET),
polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate
(PC), nylon, polyetheretherketone (PEEK), polysulfone (PSF),
polyetherimide (PEI), polyarylate (PAR), polybutylene terephthalate
(PBT), or the like is preferable.

[0097]The present invention of the above-mentioned aspect is further
illustrated in detail by the following Embodiments.

Embodiment 1

[0098]Embodiment of the present invention will be described with reference
to FIGS. 3 to 5. In this embodiment, a method of manufacturing CMOS
circuit at the same time, which is complementary combining an n-channel
type TFT and a p-channel type TFT on a same substrate is explained in
detail.

[0099]First, the nitride layer 101, the oxide layer 102 and the base
insulating film 103 are formed on the substrate 100, after a
semiconductor film having a crystal structure was obtained, a
semiconductor layers 104 to 105 isolated in a island shape are formed by
etching processing in the desired shape.

[0100]As the substrate 100, the glass substrate (#1737) is used.

[0101]Moreover, as the metal layer 101, an element selected from Ti, Al,
Ta, W, Mo, Cu, Cr, Nd, Fe, Ni, Co, Ru, Rh, Pd, Os, It and Pt, or a single
layer consisted of alloy materials or compound materials whose principal
components are the foregoing elements or a lamination of these may be
used. More preferably, a single layer consisted of these nitrides, for
example, titanium nitride, tungsten nitride, tantalum nitride, molybdenum
nitride or a lamination of these may be used. Here, titanium nitride film
having film thickness of 100 nm is utilized by a sputtering method. Also,
when the adhesion of the nitride layer 101 to the substrate 100, a buffer
layer may be provided therebetween.

[0102]Moreover, as the oxide layer 102, a single layer consisted of a
silicon oxide material or a metal oxide material, or a lamination of
these may be used. Here, a silicon oxide film having film thickness of
200 nm by a sputtering method is used. The bond strength between the
nitride layer 101 and the oxide layer 102 is strong in heat treatment,
the film peeling (also referred to as solely "peeling") or the like does
not occur. However, it can be easily peeled off on the inside of the
oxide layer or on the interface by the physical means.

[0103]Subsequently, as a base insulating layer 103, a silicon oxynitride
film (composition ratio Si=32%, O=27%, N=24% and H=17%) prepared from the
raw material gases SiH4, NH3, and N2O was formed
(preferably, 10 to 200 nm) in thickness of 50 nm at 400° C. of the
film formation temperature by a plasma CVD method. Subsequently, after
the surface was washed by ozone water, the oxide film of the surface was
removed by dilute hydrofluoric acid (1:100 dilution). Subsequently, a
silicon oxynitride film 103b (composition ratio Si=32%, O=59%, N=7% and
H=2%) prepared from the raw material gases SiH4 and N2O was
lamination-formed in thickness of 100 nm (preferably, 50 to 200 nm) at
400° C. of the film formation temperature by a plasma CVD method,
and further, a semiconductor layer (here, an amorphous silicon layer)
having an amorphous structure was formed in thickness of 54 nm
(preferably, 25 to 80 nm) at 300° C. of the film formation
temperature without the air release by a plasma CVD method.

[0104]In this embodiment, although the base film 103 is shown as a
two-layer structure, a single layer film of the foregoing insulating film
or a layer as a structure in which two layers or more are laminated may
be formed. Moreover, there are no limitations to materials for a
semiconductor film, but preferably, it may be formed using a silicon or a
silicon germanium (SixGe1-x (X=0.0001-0.02)) alloy or the like
by the known methods (sputtering method, LPCVD method, plasma CVD method
or the like). Moreover, a plasma CVD apparatus may be single wafer type
apparatus, or batch type apparatus. Moreover, the base insulating film
and the semiconductor film may be continuously formed in the same film
formation chamber without contacting with the air.

[0105]Subsequently, after the surface of the semiconductor film having an
amorphous structure was washed, an oxide film having an extremely thin
thickness of about 2 nm is formed on the surface with ozone water.

[0106]Next, nickel acetate solution containing 10 ppm of nickel in the
weight conversion was coated by a spinner. A method of spreading over the
entire surface with nickel element by a sputtering method instead of
coating may be employed.

[0107]Subsequently, a semiconductor film having a crystal structure was
formed by performing the heat treatment and crystallizing it. For this
heat treatment, the heat treatment of an electric furnace or the
irradiation of strong light may be used. In the case where it is
performed by utilizing the heat treatment of the electric furnace, it may
be performed at 500° C. to 650° C. for 4 to 24 hours. Here,
after the heat treatment (500° C., one hour) for dehydrogenation
was carried out, a silicon film having a crystal structure was obtained
by performing the heat treatment for crystallization (550° C., 4
hours). It should be noted that although here, crystallization was
performed using the heat treatment by the furnace, however, the
crystallization may be performed by a lamp anneal apparatus. It should be
noted that here, a crystallization technology using nickel as a metal
element for promoting the crystallization of silicon is used. However,
the other known crystallization technology, for example, solid phase
crystallization method or laser crystallization method may be used.

[0108]Subsequently, after the oxide film of the surface of the silicon
film having a crystal structure was removed by dilute hydrofluoric acid
or the like, the irradiation of the first laser beam (XeCl: wavelength
308 nm) for enhancing the crystallization ratio and repairing the
defaults remained within the crystal grain is performed in the air, or in
the oxygen atmosphere. For a laser beam, an excimer laser beam of 400 nm
or less of wavelength, the second higher harmonic wave, the third higher
harmonic wave of YAG laser are used. When the pulse laser beam having
about 10 to 1000 Hz of repeated frequency is used, the relevant laser
beam is condensed at 100 to 500 mJ/cm2 by an optical system,
irradiated with overlap ratio of 90 to 95% and it may be made it scan the
surface of the silicon film. Here, the irradiation of the first laser
beam is performed at repeated frequency of 30 Hz, 393 mJ/cm2 of
energy density in the air. It should be noted that since it is performed
in the air, or in the oxygen atmosphere, an oxide film is formed on the
surface by the irradiation of the first laser beam.

[0109]Subsequently, after the oxide film formed by irradiation of the
first laser beam was removed by dilute hydrofluoric acid, the irradiation
of the second laser beam is performed in the nitrogen atmosphere or in
the vacuum, thereby flattening the surface of the semiconductor film. For
this laser beam (the second laser beam), an excimer laser beam having a
wavelength of 400 nm or less, the second higher harmonic wave, the third
higher harmonic wave of YAG laser are used. The energy density of the
second laser beam is made larger than the energy density of the first
laser beam, preferably, made larger by 30 to 60 mJ/cm2. Here, the
irradiation of the second laser beam is performed at 30 Hz of the
repeated frequency and 453 mJ/cm2 of energy density, P-V value (Peak
to Valley, difference between the maximum value and minimum value) of the
concave and convex in the surface of the semiconductor film is to be 50
nm or less. This P-V value is obtained by an AFM (atomic force
microscope).

[0110]Moreover, in this embodiment, the irradiation of the second laser
beam was performed on the entire surface. However, since the reduction of
the OFF-state current is particularly effective to the TFT of the pixel
section, a step of selectively irradiating may be made on the pixel
section at least.

[0111]Subsequently, a barrier layer consisted of an oxide film of total 1
to 5 nm in thickness is formed by processing the surface with ozone water
for 120 seconds.

[0112]Subsequently, an amorphous silicon film containing argon element
which is to be gettering site is formed in film thickness of 150 nm on
the barrier layer by a sputtering method. The film formation conditions
by a sputtering method of this embodiment are made as 0.3 Pa of film
formation pressure, 50 (sccm) of gas (Ar) volumetric flow rate, 3 kW of
film formation power, and 150° C. of the substrate temperature. It
should be noted that the atomic percentage of argon element contained in
the amorphous silicon film under the above-described conditions is in the
range from 3×1020/cm3 to 6×1020/cm3, the
atomic percentage of oxygen is in the range from
1×1019/cm3 to 3×1019/cm3. Then, the
gettering is performed by carrying out the heat treatment at 650°
C. for 3 minutes using a lamp anneal apparatus.

[0113]Subsequently, after the amorphous silicon film containing argon
element that is the gettering site was selectively removed by using the
barrier layer as an etching stopper, the barrier layer is selectively
removed with dilute hydrofluoric acid. It should be noted that since when
gettering, nickel tends to easily move into the higher oxygen density
region, it is desirable that the barrier layer consisted of an oxide film
is removed after the gettering. In this embodiment, an example of
conducting a gettering with argon element is shown, however it is not
limited to this method. Another gettering method can also be used.

[0114]Subsequently, after a thin oxide film is formed with the ozone water
on the surface of the silicon film (also referred to as "polysilicon
film") having the obtained crystal structure, a mask consisted of a
resist is formed, and the semiconductor layers 104 and 105 isolated in an
island shape is formed in the desired shape by etching processing. After
the semiconductor layer was formed, the mask consisted of the resist is
removed.

[0115]Subsequently, the oxide film was removed by an etchant containing
hydrofluoric acid, and at the same time, the surface of the silicon film
was washed, an insulating film whose principal component is silicon and
which is to be a gate insulating film 106 is formed. In this embodiment,
a silicon oxynitride film (composition ratio Si=32%, O=59%, N=7% and
H=2%) is formed in thickness of 115 nm by plasma CVD method.

[0116]Subsequently, as shown in FIG. 3B, the first electrically conductive
film 107 having film thickness of 20 to 100 nm and the second
electrically conductive film 108 having film thickness of 100 to 400 nm
are lamination-formed on the gate insulating film 106. In this
embodiment, a tantalum nitride film having film thickness of 50 nm and a
tungsten film having film thickness of 370 nm are laminated sequentially
on the gate insulating film 106.

[0117]As an electrically conductive material for forming the first
electrically conductive film and the second electrically conductive film,
it is formed using an element selected from Ta, W, Ti, Mo, Al and Cu, or
alloy material or compound material whose principal component is the
foregoing element. Moreover, as the first electrically conductive film
and the second electrically conductive film, a semiconductor film
represented by a polycrystal silicon film in which impurity element such
as phosphorus or the like is doped, and AgPdCu alloy may be used.
Moreover, it is not limited to a two-layer structure. For example, it may
be made a three-layer structure in which a tungsten film having film
thickness of 50 nm, aluminum-silicon (Al--Si) alloy having film thickness
of 500 nm, and a titanium nitride film having film thickness of 30 nm are
in turn laminated. Moreover, in the case of a three-layer structure,
instead of tungsten of the first electrically conductive film, tungsten
nitride may be used, instead of aluminum-silicon (Al--Si) alloy of the
second electrically conductive film, aluminum-titanium (Al--Ti) alloy
film may be used, or instead of a titanium nitride film of the third
electrically conductive film, a titanium film may be used. Moreover, it
may be a single layer structure.

[0118]Next, as shown in FIG. 3C, mask 109 consisted of resists are formed
by light exposure step, the first etching processing for forming a gate
electrode and wirings is performed. As for an etching, ICP (Inductively
Coupled Plasma) etching method may be used. The film can be etched in the
desired tapered shape by appropriately adjusting the etching conditions
(electric energy applied to the coil type electrode, electric energy
applied to the electrode on the substrate side, temperature of electrode
on the substrate side and the like). It should be noted that as gas for
an etching, chlorine based gas which is represented by Cl2,
BCl3, SiCl4, CCl4 or the like, fluorine based gas which is
represented by CF4, SF6, NF3 or the like or O2 can be
appropriately used.

[0119]Under the first conditions given above, the edges of the films can
be tapered owing to the shape of the resist mask and the effect of the
bias voltage applied to the substrate side. The angle of the tapered
portion is set to 15 to 45°. In order to etch the films without
leaving any residue on the gate insulating film, the etching time is
prolonged by about 10 to 20%. The selective ratio of the silicon
oxynitride film to the W film is 2 to 4 (typically, 3), and hence the
exposed surface of the silicon oxynitride film is etched by about 20 to
50 nm through the over-etching treatment. Through the first etching
treatment, first shape conductive layers 110 and 111 (first conductive
layers 110a and 111a and second conductive layers 110b and 111b) are
formed from the first conductive film and the second conductive film.
Denoted by 112 is a gate insulating film and a region of the gate
insulating film which is not covered with the first shape conductive
layers is etched and thinned by about 20 to 50 nm.

[0120]Then the first doping treatment is performed to dope the film with
an n type impurity (donor) as shown in FIG. 3D. The doping is made by ion
doping or ion implantation. In ion doping, the dose is set to
1×1013 to 5×1014 atoms/cm2. Used as the
impurity element for imparting the n type conductivity is a Group 5
element, typically phosphorus (P) or arsenic (As). In this case, the
first shape conductive layers 110 and 111 serve as masks against the
element used for the doping and the acceleration voltage is adjusted
appropriately (20 to 60 keV, for example). The impurity element thus
passes through the gate insulating film 112 to form impurity regions (n+
region) 113 and 114. The phosphorus (P) concentration in first impurity
regions (n+ region) is set to 1×1020 to 1×1021
atoms/cm3.

[0121]Then the second doping treatment is carried out as shown in FIG. 4A.
This time, the film is doped with an n-type impurity (donor) in a dose
smaller than in the first doping treatment at a high acceleration
voltage. For example, the acceleration voltage is set to 70 to 120 keV
and the dose is set to 1×1013 atoms/cm3. As a result,
impurity regions are formed inside the first impurity regions that have
been formed in the island-like semiconductor films in FIG. 3D. In the
second doping treatment, the second conductive films 110b and 111b are
used as masks against the impurity element and the impurity element
reaches regions below the first conductive films 110a and 111a. Thus
formed are impurity regions (n- region) 115 and 116 that overlap the
first conductive films 110a and 111a, respectively. Since the remaining
first conductive layers 110a and 111a have almost the uniform thickness,
the concentration difference along the first conductive layers is not
large and the concentration in the impurity regions is 1×1017
to 1×1019 atoms/cm3.

[0122]The second etching treatment is then conducted as shown in FIG. 4B.
In this etching treatment, ICP etching is employed, CF4 and Cl2
and O2 are mixed as etching gas, and plasma is generated by giving
RF (13.56 MHz) power of 500 W to a coiled electrode at a pressure of 1
Pa. RF (13.56 MHz) power of 50 W is also given to the substrate side
(sample stage) so that a self-bias voltage lower than that of the first
etching treatment can be applied. The tungsten film is subjected to
anisotropic etching under these conditions so that the tantalum nitride
film or the titanium film serving as the first conductive layers is
remained. In this way, second shape conductive layers 117 and 118 (first
conductive films 117a and 118a and second conductive films 117b and 118b)
are formed. Denoted by 119 is a gate insulating film and a region of the
gate insulating film which is not covered with the second shape
conductive layers 117 and 118 is further etched and thinned by about 20
to 50 nm.

[0123]Then a resist mask 120 is formed as shown in FIG. 4C so that the
island-like semiconductor layer for forming the p-channel TFT is doped
with a p type impurity (acceptor). Typically, boron (B) is used. The
impurity concentration in impurity regions (p+ region) 121 and 122 is set
to 2×1020 to 2×1021 atoms/cm3. Thus the
regions are doped with boron in a concentration 1.5 to 3 times higher
than the concentration of phosphorus that has already been contained in
the regions, thereby inverting the conductive type of the regions.

[0124]The impurity regions are formed in each semiconductor layer through
the above steps. The second shape conductive layers 117 and 118 serve as
gate electrodes. Thereafter, as shown in FIG. 4D, a protective insulating
film 123 is formed of a silicon nitride film or a silicon oxynitride film
by plasma CVD. The impurity elements that is doped the semiconductor
layers are then activated for controlling the conductivity type.

[0125]A silicon nitride film 124 is formed and subjected to hydrogenation.
Hydrogen is released from the silicon nitride film 124 as a result and
hydrogen diffuses to the semiconductor layers. The semiconductor layers
are thus hydrogenated.

[0126]An interlayer insulating film 125 is formed of an organic insulating
material such as polyimide and acrylic. A silicon oxide film formed by
plasma CVD using TEOS may of course be adopted instead, but it is
desirable to choose the above organic insulating material from the
viewpoint of improving levelness.

[0127]Contact holes are formed next, so that source or drain wirings 126
to 128 are formed from Al, Ti, Ta or the like.

[0128]In accordance with the above processes, a CMOS circuit obtained by
combining an n-channel TFT and a p-channel TFT complementally is obtained
A p-channel TFT has a channel formation region 130, and has the impurity
regions 121 and 122 that function as source regions or drain regions.

[0129]A n-channel TFT has a channel formation region 131; an impurity
region 116a (gate overlapped drain: GOLD region) overlapping the gate
electrode 118 that is formed of the second shape conductive layer; an
impurity region 116b (LDD region) formed outside the gate electrode; and
an impurity region 119 functioning as a source region or a drain region.

[0130]The CMOS TFT as such can be used to form a part of a driver circuit
of an active matrix light emitting device or an active matrix liquid
crystal display device. Besides, the n-channel TFT or the p-channel TFT
as above can be applied to a transistor for forming a pixel section.

[0131]Using the CMOS circuits of this embodiment in combination, a basic
logic circuit or a more intricate logic circuit (such as a signal divider
circuit, a D/A converter, an operation amplifier and a γ correction
circuit) can be formed. It also can constitute a memory or a
microprocessor.

Embodiment 2

[0132]An example of fabrication of a light emitting device having an OLED
and using the TFTs obtained in accordance with Embodiment 1 will be
described with reference to FIG. 5.

[0133]FIG. 5 shows an example of a light emitting device (in a state
before sealing) having a pixel portion and a drive circuit for driving
the pixel portion, the pixel portion and the drive circuit being formed
on one insulating member. A CMOS circuit forming a basic unit in the
drive circuit and one pixel in the pixel portion are illustrated. The
CMOS circuit can be obtained in accordance with Embodiment 1.

[0134]Referring to FIG. 5, a substrate 200, a nitride layer 201 and an
oxide layer 202 are provided. On a base insulating layer 203 formed on
the element formation substrate, the drive circuit 204 constituted of an
n-channel TFT and a p-channel TFT, a switching TFT, which is a p-channel
TFT, and a current control TFT, which is an n-channel TFT, are formed. In
this embodiment, each of the TFTs is formed as a top gate TFT.

[0135]The n-channel TFT and p-channel TFT are the same as those in
Embodiment 1. The description for them will not be repeated. The
switching TFT is a p-channel TFT of a structure having two channel
forming regions between a source region and a drain region (double-gate
structure). In this embodiment, the structure of the switching TFT is not
limited to the double-gate structure, and the switching TFT may
alternatively have a single-gate structure in which only one channel
forming region is formed or a triple-gate structure in which three
channel forming regions are formed.

[0136]A contact hole is formed in a first interlayer insulating film 207
above the drain region 206 of the current control TFT before a second
interlayer insulating film 208 is formed. This is for the purpose of
simplifying the etching step when a contact hole is formed in the second
interlayer insulating film 208. A contact hole is formed in the second
interlayer insulating film 208 so as to reach the drain region 206, and a
pixel electrode 209 connected to the drain region 206 is formed in the
contact hole. The pixel electrode 209 functions as the cathode of the
OLED and is formed by using a conductive film containing an element
belonging to the group I or II in the periodic table. In this embodiment,
a conductive film of a compound composed of lithium and aluminum is used.

[0137]An insulating film 213 is formed so as to cover an end portion of
the pixel electrode 209. The insulating film 213 will be referred to as a
bank in this specification. The bank 213 may be formed of an insulating
film containing silicon or a resin film. If a resin film is used, carbon
particles or metal particles may be added to set the specific resistance
of the resin film to 1×106 to 1×1012 Ωm
(preferably 1×108 to 1×1010 Ωm), thereby
reducing the possibility of dielectric breakdown at the time of film
forming.

[0138]The OLED 210 is formed by the pixel electrode (cathode) 209, an
organic compound layer 211, and an anode 212. As the anode 212, a
conductive film of a large work function, typically an oxide conductive
film is used. As this oxide conductive film, indium oxide, tin oxide,
zinc oxide or some other compound of these elements may be used.

[0139]In this specification, "organic compound layer" is defined as a
generic name for a multilayer formed by combining with a light emitting
layer a hole injection layer, a hole transporting layer, a hole blocking
layer, an electron transporting layer, an electron injection layer, or an
electron blocking layer. However, the organic compound layer may comprise
a single layer of organic compound film.

[0140]The material of the light emitting layer is an organic compound
material but not limited to a particular one. It may be a high-molecular
weight material or a low-molecular weight material. For example, a thin
film formed of a light emitting material capable of emitting light by
duplet excitation or a thin film formed of a light emitting material
capable of emitting light by triplet excitation may be used as the light
emitting layer.

[0141]It is effective to form a passivation film (not shown) so as to
completely cover the OLED 210 after the formation of the anode 212. A
film having thermal conductivity, e.g., film of aluminum nitride,
aluminum nitroxide, or beryllium oxide is suitably used as the
passivation film. Also, an insulating film comprising a diamondlike
carbon (DLC) film, a silicon nitride film or a silicon nitroxide film, or
a multilayer formed of a combination of such films may be used as the
passivation film.

[0142]To protect the OLED 210, steps including a step for attaching a
supporting member as described above with respect to the embodiment mode
and a sealing (enclosing) step are performed. Thereafter, the substrate
200 on which the nitride layer 201 is formed is stripped off. An example
of the light emitting device after this step will be described with
reference to FIGS. 6A and 6B. The transfer member 22 in FIG. 2D
corresponds to a film substrate 600.

[0143]FIG. 6A is a top view of an EL module, and FIG. 6B is a
cross-sectional view taken along the line A-A' of FIG. 6A. Referring to
FIG. 6A, a film 601 having thermal conductivity (e.g., aluminum nitride
film) is formed on the flexible film substrate 600 (e.g., a plastic
substrate), and a pixel portion 602, a source-side drive circuit 604, and
a gate-side drive circuit 603 are formed on the film 601. The pixel
portion and the drive circuits can be obtained in the same manner as
those described above with respect to Embodiments 1 and 2.

[0144]An organic resin 618 and a protective film 619 are provided. The
pixel portion and the drive circuit portions are covered with the organic
resin 618 and the surface of the organic resin 618 is covered with the
protective film 619. These portions are enclosed with a cover member 620
using an adhesive. The cover member 620 is bonded as a supporting member
before debonding of the element layer. It is desirable that a member made
of the same material as the film substrate 600, e.g., a plastic substrate
be used as the cover member 620, such that the cover member 620 is
prevented from being deformed by heat or external force. For example, a
member which is worked so as to form a cavity (having a depth of 3 to 10
μm) as shown in FIG. 6B is used. It is also desirable that the cover
member be further worked to form a recess (having a depth of 50 to 200
μm) capable of accommodating a desiccant 621. If the EL module is
manufactured on a gang board, the gang board may be cut after bonding
between the substrate and the cover member. The gang board is cut with a
CO2 laser or the like so that end surfaces are aligned.

[0145]Wiring 608 is provided for transmission of signals input to the
source-side drive circuit 604 and the gate-side drive circuit 603. A
video signal and a clock signal from a flexible printed circuit (FPC) 609
provided as an external input terminal are received through the wiring
608. Although only the FPC is illustrated, a printed wiring board (PWB)
may be attached to the FPC. The light emitting device described in this
specification comprises an arrangement including not only the light
emitting device main unit but also the FPC or PWB in the attached state.

[0146]The structure of the light emitting device as seen in a cross
section will next be described with reference to FIG. 6B. The film 601
having thermal conductivity is formed on the film substrate 600, the
insulating film 610 is formed on the film 601, and the pixel portion 602
and the gate-side drive circuit 603 are formed above the insulating film
610. The pixel portion 602 is formed by a plurality of pixels including a
current control TFT 611 and a pixel electrode 612 electrically connected
to the drain of the current control TFT 611. The gate-side drive circuit
603 is formed by using a CMOS circuit having a combination of an
n-channel TET 613 and a p-channel TFT 614.

[0147]These TFTs (611, 613, 614, etc.) may be fabricated in the same
manner as the n-channel TFT of Embodiment 1 and the p-channel TFT of
Embodiment 1.

[0148]After the pixel portion 602, the source-side drive circuit 604 and
the gate-side drive circuit 603 have been formed on one substrate in
accordance with Embodiments 1 and 2, the supporting member (cover member
in this embodiment) is bonded, the substrate (not shown) is debonded, the
film 601 (e.g., aluminum nitride film) having thermal conductivity is
formed on the insulating film 610, and the film substrate 600 is
thereafter adhered, as shown in FIG. 1C and FIG. 2A to 2C. A bonding
layer, which is not shown, is provided between the film 601 having
thermal conductivity and the film substrate 600 to bond these films to
each other.

[0149]In the case where the cover member 620 is formed so as to have a
cavity as shown in FIG. 6B, no portion of the supporting member exists
adjacent to the insulating film 610 in the portion (connection portion)
corresponding to the wiring lead-out terminal at the time of debonding of
the element layer after bonding of the cover member 620 provided as the
supporting member, so that the mechanical strength of this portion is
low. Therefore, it is desirable that the FPC 609 be attached before
debonding and fixed by an organic resin 622.

[0150]In addition, as the insulating film provided between the TFT and the
OLED, a material which not only blocks diffusion of an impurity ion such
as an alkali metal ion, an alkali earth metal ion, but also aggressively
adsorbs the impurity ion such as an alkali metal ion and an alkali earth
metal ion may be preferable. Furthermore, a material which resists the
temperature in the following process may be more preferable. One example
of the material suitable for these conditions includes a silicon nitride
film containing fluorine in a large amount. The concentration of the
fluorine contained in the silicon nitride film may be
1×1019/cm3 or more, and preferably, the composition ratio
of the fluorine in the silicon nitride film may be 1 to 5%. The fluorine
in the silicon nitride film binds to an alkali metal ion, an alkali earth
metal ion, or the like, which is adsorbed in the silicon nitride film.
Another example includes an organic resin film containing particles
consisting of an antimony (Sb) compound, a tin (Sn) compound, or an
indium (In) compound, which adsorbs an alkali metal ion, an alkali earth
metal ion, or the like, e.g. an organic resin film including particles of
antimony pentoxide (Sb2O5.nH2O). This organic resin film
includes particles with an average particle diameter of 10 to 20 nm, and
the light transmittance of this film is very high. The antimony compounds
represented by the particles of antimony pentoxide can easily adsorb the
impurity ion such as an alkali metal ion, and alkali earth metal ion.

[0151]The pixel electrode 612 functions as the cathode of the light
emitting device (OLED). Banks 615 are formed at opposite ends of the
pixel electrode 612, and an organic compound layer 616 and an anode 617
of the light emitting element are formed on the pixel electrode 612.

[0152]The organic compound layer 616 (for emission of light and movement
of carriers for causing emission of light) may be formed by freely
selecting a combination of a light emitting layer and a charge
transporting layer or a charge injection layer. For example, a
low-molecular weight organic compound material or a high-molecular weight
organic compound material may be used to form the organic compound layer
616. Also, a thin film formed of a light emitting material (singlet
compound) capable of emission of light (fluorescence) by singlet
excitation or a thin film formed of a light emitting material (triplet
compound) capable of emission of light (phosphorescence) by triplet
excitation may be used as the organic compound layer 616. An inorganic
material such as silicon carbide may be used as a charge transporting
layer or a charge injection layer. These organic and inorganic materials
may be selected from well-known materials.

[0153]The anode 617 also functions as a common wiring element connected to
all the pixels and is electrically connected to the FPC 609 via
connection wiring 608. All the elements included in the pixel portion 602
and the gate-side drive circuit 603 are covered with the anode 617, the
organic resin 618 and the protective film 619.

[0154]It is preferred that a material higher in transparency or
translucency to visible light be used as the organic resin 618. Also, it
is desirable that a material higher in ability to limit permeation of
water and oxygen be used as the organic resin 618.

[0155]Also, it is preferred that after the light emitting element has been
completely covered with the organic resin 618, the protective film 619 be
at least formed on the surface (exposed surface) of the organic resin 618
as shown in FIGS. 6A and 6B. The protective film may be formed on the
entire surface including the back surface of the substrate. In such a
case, it is necessary to carefully form the protective film so that no
protective film portion is formed at the position where the external
input terminal (FPC) is provided. A mask may be used to prevent film
forming of the protective film at this position. The external input
terminal portion may be covered with a tape such as a tape made of Teflon
(registered trademark) used as a masking tape in a CVD apparatus to
prevent film forming of the protective film. A film having thermal
conductivity like the film 601 may be used as the protective film 619.

[0156]The light emitting element constructed as described above is
enclosed with the film 601 having thermal conductivity and the protective
film 619 to completely isolate the light emitting element from the
outside, thus preventing materials such as water and oxygen which
accelerate degradation of the organic compound layer by oxidation from
entering from the outside. Also, the film having thermal conductivity
enables dissipation of produced heat. Thus, the light emitting device
having improved reliability is obtained.

[0157]Another arrangement is conceivable in which a pixel electrode is
used as an anode and an organic compound layer and a cathode are formed
in combination to emit light in a direction opposite to the direction
indicated in FIG. 6B. FIG. 7 shows an example of such an arrangement.
This arrangement can be illustrated in the same top view as FIG. 6A and
will therefore be described with reference to a cross-sectional view
only.

[0158]The structure shown in the cross-sectional view of FIG. 7 will be
described. An insulating film 710 is formed on a film substrate 700, and
a pixel portion 702 and a gate-side drive circuit 703 are formed over the
insulating film 710. The pixel portion 702 is formed by a plurality of
pixels including a current control TFT 711 and a pixel electrode 712
electrically connected to the drain of the current control TFT 711. After
the layer to be debonded, which is formed on a substrate in accordance
with the above-described embodiment mode of the present invention, has
been debonded, a film 701 having thermal conductivity is formed on the
surface of the layer to be debonded. Further, the film substrate 700 is
adhered to the layer 701 having thermal conductivity. A bonding layer,
which is not shown, is provided between the film 701 having thermal
conductivity and the film substrate 700 to bond these films to each
other. A gate-side drive circuit 703 is formed by using a CMOS circuit
having a combination of an n-channel TET 713 and a p-channel TFT 714.

[0159]These TFTs (711, 713, 714, etc.) may be fabricated in the same
manner as the n-channel TFT 201 of Embodiment 1 and the p-channel TFT 202
of Embodiment 1.

[0160]The pixel electrode 712 functions as an anode of the light emitting
device (OLED). Banks 715 are formed at opposite ends of the pixel
electrode 712, and an organic compound layer 716 and a cathode 717 of the
light emitting element are formed over the pixel electrode 712.

[0161]The cathode 717 also functions as a common wiring element connected
to all the pixels and is electrically connected to a FPC 709 via
connection wiring 708. All the elements included in the pixel portion 702
and the gate-side drive circuit 703 are covered with the cathode 717, an
organic resin 718 and a protective film 719. A cover member 720 is bonded
to the element layer by an adhesive. A recess is formed in the cover
member and a desiccant 721 is set therein.

[0162]In the case where the cover member 720 is formed so as to have a
cavity as shown in FIG. 7, no portion of the supporting member exists
adjacent to the insulating film 710 in the portion corresponding to the
wiring lead-out terminal at the time of debonding of the element layer
after bonding of the cover member 720 provided as the supporting member,
so that the mechanical strength of this portion is low. Therefore, it is
desirable that the FPC 709 be attached before debonding and fixed by an
organic resin 722.

[0163]In the arrangement shown in FIG. 7, the pixel electrode is used as
the anode while the organic compound layer and the cathode are formed in
combination, so that light is emitted in the direction of the arrow in
FIG. 7.

[0164]While the top gate TFTs have been described by way of example, the
present invention can be applied irrespective of the TFT structure. For
example, the present invention can be applied to bottom gate (inverted
staggered structure) TFTs and staggered structure TFTs.

Embodiment 3

[0165]While an example of use of the top gate TFT in Embodiment 2 has been
described, a bottom gate TFT can also be used. An example of an
arrangement using a bottom gate TFT will be described with reference to
FIG. 8.

[0166]As shown in FIG. 8, each of an n-channel TFT 913, a p-channel TFT
914, and an n-channel TFT 911 is of the bottom gate structure. The TFTs
in the bottom gate structure may be fabricated by using well-known
techniques. The active layer of these TFTs may be a semiconductor film
having a crystalline structure (e.g., polysilicon) or a semiconductor
film having an amorphous structure (e.g., amorphous silicon).

[0167]In FIG. 8 are illustrated a flexible film substrate 900 (e.g., a
plastic substrate), a film 901 having thermal conductivity (e.g.,
aluminum nitride film), a pixel portion 902, a gate-side drive circuit
903, an insulating film 910, a pixel electrode (cathode) 912, a bank 915,
an organic compound layer 916, an anode 917, an organic resin 918, a
protective film 919, a cover member 920, a desiccant 921, and an organic
resin 922. A bonding layer, which is not shown, is provided between the
film 901 having thermal conductivity and the film substrate 900 to bond
these films to each other.

[0168]The arrangement is the same as that of Embodiment 3 except for the
n-channel TFT 913, the p-channel TFT 914 and the n-channel TFT 911. The
description of the same details will not be repeated.

Embodiment 4

[0169]In this embodiment, when an organic compound layer is formed by an
ink jet method, the organic compound layer is continuously formed through
a plurality of pixels. More specifically, an example of formation in
which the organic compound layer is formed in a stripe form on each of
columns or rows of pixel electrodes arranged in correspondence with a
matrix with m rows and n columns will be described. Also, the organic
compound layer is formed in an oblong or rectangular shape in
correspondence with each pixel electrode.

[0170]FIGS. 9A, 9B, and 9C are diagrams illustrating this embodiment. FIG.
9A shows an arrangement in which a pixel portion 802, a
scanning-line-side drive circuit 803 and a data-line-side drive circuit
804 are provided on a substrate 801. A separation layer 805 is provided
in the form of lands in a striped pattern in the pixel portion 802, and
the organic compound layer is formed between each adjacent pair of the
separation layer lands. The separation layer 805 is provided for the
purpose of preventing each adjacent pair of the organic compound layer
portions from mixing when the organic compound layer is formed by an ink
jet method.

[0171]The organic compound layer 806 is formed by jetting from an ink head
807 a solution containing an organic compound material. The material of
the organic compound layer is not limited to a particular one. However,
if a multicolor is performed, organic compound layers 806R, 806G, and
806B may be provided in correspondence with red, green and blue.

[0172]FIG. 9B is a cross-sectional view of the structure schematically
shown in FIG. 9A, showing a state in which the scanning-line-side drive
circuit 803 and the pixel portion 802 are formed on the substrate 801.
The lands of separation layer 805 are formed in the pixel portion 802,
and organic compound layers 806R, 806G, and 806B are formed between the
separation layer lands. The ink head 807 is of an ink jet type. Ink
droplets 808R, 808G, and 808B corresponding to the colors, red, green and
blue are jetted from the ink head 807 according to a control signal. The
jetted ink droplets 808R, 808G, and 808B are attached to the surface of
the substrate and undergo drying and baking steps. Thereafter, the jetted
materials function as the organic compound layers. The ink head may be
moved in one direction for scanning along each column or row, so that the
processing time required to form the organic compound layers can be
reduced.

[0173]FIG. 9C is a diagram showing the pixel portion in more detail.
Current control TFTs 810 and pixel electrodes 812 connected to the
current control TFTs 810 are formed on the substrate, and the organic
compound layers 806R, 806C, and 806B are formed between the lands of the
separation layer 805 on the pixel electrodes. It is desirable that an
insulating film 811 having an alkali metal blocking effect be formed
between the pixel electrodes 812 and the current control TFTs 810.

[0174]This embodiment can be applied as the method of forming the organic
compound layer in one of the embodiment mode, Embodiment 2 and Embodiment
3.

Embodiment 5

[0175]In this embodiment, the step in which an active matrix type liquid
crystal display device is prepared by peeling off the substrate from the
active matrix substrate prepared in Embodiment 1 and adhering it with a
plastic substrate will be described below. FIG. 10 is used for the
purpose of describing it.

[0176]In FIG. 10A, the reference numeral 400 denotes a substrate, the
reference numeral 401 denotes a nitride layer, the reference numeral 402
denotes an oxide layer, the reference numeral 403 denotes a base
insulating layer, the reference numeral 404a denotes an element of a
driver circuit 413, the reference numeral 404b denotes an element 404b of
the pixel section 414 and the reference numeral 405 denotes a pixel
electrode. Here, the term "element" is referred to a semiconductor
element (typically, TFT) or MIM element or the like used for a switching
element of pixels in an active matrix type liquid crystal display device.
In addition, an active layer of the switching element can be both a
semiconductor having a crystal structure film (polysilicon film and the
like) and a semiconductor film (amorphous silicon and the like) having an
amorphous structure.

[0177]First, according to Embodiment 1, n-channel type TFT, one of which
electrode is a a pixel electrode, is formed. Further, N-channel TFT and
p-channel TFT are formed on the driver circuit 413 respectively on the
same substrate as the substrate on which the above n-channel TFT with the
pixel electrode is formed. Subsequently, after the active matrix
substrate of the state in FIG. 10A was obtained, an orientation film 406a
is formed on the active matrix substrate of FIG. 10A, and a rubbing
processing is performed. It should be noted that in this embodiment,
before the orientation film is formed, a spacer in a column shape (not
shown) for retaining a substrate interval was formed at the desired
position by patterning an organic resin film such as an acryl resin or
the like. Moreover, instead of a spacer in a column shape, a spacer in a
sphere shape may be scattered over the whole surface of the substrate.

[0178]Moreover, in this embodiment, it is preferable that films that is
mainly contained Al or Ag or lamination of these films that have well
reflectivity are used for forming a pixel electrode, but when the pixel
electrode is formed by a transparent conductive film, although the number
of photo-masks increases by one sheet, a transparent type display device
can be formed.

[0179]Subsequently, an opposing substrate which is to be a supporting
member 407 is prepared for. A color filter (not shown) in which a colored
layer and a shielding layer were arranged corresponding to the respective
pixels has been provided on this opposing substrate. Moreover, a
shielding layer was provided on the portion of the driver circuit. A
flattening film (not shown) for covering this color filter and the
shielding layer was provided. Subsequently, an opposing electrode 408
consisted of a transparent conductive film was formed on the flattening
film in the pixel section, an orientation film 406b was formed on the
whole surface of the opposing substrate, and the rubbing processing was
provided.

[0180]Then, an active matrix substrate 400 in which the pixel section and
the driver circuit were formed and the supporting member 407 are adhered
together with a sealing medium which is to be an adhesive layer 409. Into
a sealing medium, filler is mixed, two sheets of substrates are adhered
together with uniform interval by this filler and a spacer in a column
shape. Then, between both substrates, a liquid crystal material 410 is
implanted and completely sealed with a sealing compound (not shown) (FIG.
10B). As the liquid crystal material 410, the known liquid crystal
material may be used.

[0181]Next, the substrate 400 provided a nitride layer or a metal layer
401 is peeled off by physical means. (FIG. 10C) The substrate 400 can be
peeled off by comparatively small power, because the membrane stress of
the oxide layer 402 is different from that of the nitride layer 401.

[0182]The film 415 having the heat conductivity is formed on the face that
is peeled off. (FIG. 11A) The film 415 having the heat conductivity can
repair a crack due to peeling. As the film 415 having the heat
conductivity, a nitride aluminum (AlN), an oxynitride aluminum (AlNO),
and an oxynitride beryllium oxide (BeO) can be used. Further, it is
preferable for the film 415 having the heat conductivity to be
transparent film or a translucent film as against visible light. In this
embodiment, the nitride aluminum (AlN) having 2.85 W/cmK extremely high
heat conductivity rate and 6.28 eV (RT) energy gap is formed by
sputtering.

[0183]Subsequently, the film 415 having the heat conductivity is adhered
with an adhesive layer 411 consisted of an epoxy resin or the like on a
transfer member 412. In this embodiment, the transfer member 412 can be
made light by using plastic film substrate. In this way, a flexible
liquid crystal module is completed. The liquid crystal module can prevent
an element from deterioration by emitting the generation of heat occurred
by elements 404a to 404c by using the film 415 having the heat
conductivity. The film 415 having the heat conductivity can prevent
transformation and a change in quality of a transfer member that is weak
to heat. Then, if necessary, the flexible substrate 412 or an opposing
substrate is cut down in the desired shape. Furthermore, a polarizing
plate (not shown) or the like was appropriately provided using the known
technology. Then, a FPC (not shown) was attached using the known
technology. At the time of debonding of the element layer after bonding
of the cover member 620 provided as the supporting member, so that the
mechanical strength of this portion is low. Therefore, it is desirable
that the FPC 609 be attached before debonding and fixed by an organic
resin 622. In addition, after that the substrate is peeled off, the
opposite substrate is bonded, the wiring drawing portion (a connecting
portion) become only peeled off layer so that the mechanical strength
become weak. Thus, it is preferable that the peeled off layer is adhered
over with FPC before peeling off and fixed with organic resin.

Embodiment 6

[0184]An example of a reflection type of display device in which the pixel
electrode is formed of a metallic material having a reflecting property
has been described as Embodiment 5. This embodiment is an example of a
half-transmission type of display device in which pixel electrodes are
formed of an conductive film having a light-transmitting property and a
metallic material having a reflecting property, as shown in FIG. 12.

[0185]The step of forming the interlayer insulating layer covering the
TFTs and the steps performed before this step are the same as those in
Embodiment 5, and the description for them will not be repeated. One of
two electrodes in contact with the source region or the drain region of a
TFT is formed of a metallic material having a reflecting property to form
a pixel electrode (reflecting portion) 502. Subsequently, a pixel
electrode (transmitting portion) 501 made of a conductive film having a
light-transmitting property is formed so as to overlap the pixel
electrode (reflecting portion) 502. As the conductive film having a
light-transmitting property, indium-tin oxide (ITO), indium-zinc oxide
(In2O2--ZnO) or zinc oxide (ZnO), for example, may be used.

[0186]An active matrix board is formed in the above-described manner. The
substrate is stripped off from this active matrix board in accordance
with the embodiment mode. A film 507 having thermal conductivity is
thereafter formed, a plastic substrate is bonded to the board by an
adhesive, and a liquid crystal module is made in accordance with
Embodiment 5. A backlight 504 and a light guide plate 505 are provided on
the obtained liquid crystal module. The liquid crystal module is
thereafter covered with a cover 506. An active-matrix liquid crystal
display device such as that partially shown in section in FIG. 12 is
thereby completed. The cover and the liquid crystal module are bonded to
each other by using an adhesive and an organic resin. When the plastic
substrate and the opposed substrate are bonded to each other, a space
between the opposed substrate and a frame placed so as to surround the
opposed substrate may be filled with the organic resin for bonding. Since
the display device is of a half-transmission type, polarizing plates 503
are adhered to both the plastic substrate and the opposed substrate.

[0187]When a sufficient quantity of external light is supplied, the
display device is driven as a reflection type in such a manner that while
the backlight is maintained in the off state, display is performed by
controlling the liquid crystal between the counter electrode provided on
the opposed substrate and the pixel electrodes (reflecting portions) 502.
When the quantity of external light is insufficient, the backlight is
turned on and display is performed by controlling the liquid crystal
between the counter electrode provided on the opposed substrate and the
pixel electrodes (transmitting portions) 501.

[0188]However, if the liquid crystal used is a TN liquid crystal or an STN
liquid crystal, the twist angle of the liquid crystal is changed between
the reflection type and the transmission type. Therefore, there is a need
to optimize the polarizing plate and the phase difference plate. For
example, a need arises to separately provide an optical rotation
compensation mechanism for adjusting the twist angle of the liquid
crystal (e.g., a polarizing plate using a high-molecular weight liquid
crystal).

Embodiment 7

[0189]Various modules (active matrix liquid crystal module, active matrix
EL module and active matrix EC module) can be completed by the present
invention. Namely, all of the electronic equipments are completed by
implementing the present invention.

[0193]FIG. 13C is a mobile computer which comprises: a main body 2201; a
camera section 2202; an image receiving section 2203; operation switches
2204 and a display section 2205 etc.

[0194]FIG. 13D is a goggle type display which comprises: a main body 2301;
a display section 2302; and an arm section 2303 etc.

[0195]FIG. 13E is a player using a recording medium in which a program is
recorded (hereinafter referred to as a recording medium) which comprises:
a main body 2401; a display section 2402; a speaker section 2403; a
recording medium 2404; and operation switches 2405 etc. This apparatus
uses DVD (digital versatile disc), CD, etc. for the recording medium, and
can perform music appreciation, film appreciation, games and use for
Internet.

[0196]FIG. 13F is a digital camera which comprises: a main body 2501; a
display section 2502; a view finder 2503; operation switches 2504; and an
image receiving section (not shown in the figure) etc.

[0198]FIG. 14B is a portable book (electronic book) which comprises: a
main body 3001; display sections 3002 and 3003; a recording medium 3004;
operation switches 3005 and an antenna 3006 etc.

[0199]FIG. 14C is a display which comprises: a main body 3101; a
supporting section 3102; and a display section 3103 etc.

[0200]In addition, the display shown in FIG. 14C has small and
medium-sized or large-sized screen, for example a size of 5 to 20 inches.
Further, to manufacture the display part with such sizes, it is
preferable to mass-produce by gang printing by using a substrate with one
meter on a side. As described above, the applicable range of the present
invention is extremely large, and the invention can be applied to
electronic equipments of various areas. Note that the electronic devices
of this embodiment can be achieved by utilizing any combination of
constitutions in Embodiments 1 to 6.

[0201]The film having thermal conductivity in accordance with the present
invention dissipates heat produced by elements to limit degradation of
the elements and to prevent deformation or and change in quality of a
transfer member, e.g., a plastic substrate, thus protecting the elements.
Also, the film having thermal conductivity in accordance with the present
invention prevents mixing of impurities such as water and oxygen from the
outside to protect the elements.

[0202]Even if cracks are caused in the debonded layer at the time of
debonding the debonded layer from the substrate by a physical means, the
cracked portions can be repaired by the film having thermal conductivity
in accordance with the present invention, thus improving yield as well as
the reliability of the elements.